Question 7
Triangle $ABC$ is right-angled at $B$. Points $P\in BC,Q\in AB$ satisfy $\angle PAB=\angle CAB/3$ and $\angle QCB=\angle ACB/3$. Point $R$ is inside the triangle with $\angle RAC=\angle BAP$ and $\angle RCA=\angle BCQ$. If $\angle QRC$ is an integer number of degrees, find its minimum possible value.
